The invention relates to a filter element for a fluid stream which flows into an axial end face of the filter element.
Axial flow filter elements are used in many areas where a gas or liquid must be filtered. These elements are used in all types of housings and must be replaced or cleaned as intended after specified maintenance intervals or after reaching a certain contaminant load level. It is therefore of crucial importance that it be possible to manipulate or handle the filter element because a filter element that is difficult to handle may not be cleaned or replaced at all, or the element or system may be damaged in an attempt to handle it using improper tools.
U.S. Pat. No. 6,235,195 (=EP 1,169,109) discloses an axial flow filter element, with oncoming flow at one end and outgoing flow from the opposite end without any deflection of the fluid flow. In this filter a handle is provided extending axially from the first end face and permanently connected to the filter element—preferably to the inner core of the filter element. This handle extends a sufficient distance from the end face of the filter element that problem-free handling by hand without the use of tools is possible. During the manufacturing process and/or during maintenance, such filter elements are sometimes set down on the floor or ground or on a work surface, in which case the clean end comes to rest directly on the contact surface. Especially in the case of large-volume filter elements having a certain weight and/or a large outside diameter, it may be impossible to avoid setting the filter down temporarily. Then foreign bodies may be forced into the sensitive clean end of the filter element because the surface on which the filter is placed is unclean. The channel structures of the filter element, which are sealed at alternating ends, consequently become damaged, while on the other hand the foreign bodies such as metal shavings or loose screws and nuts may be drawn into the machine assembly, such as an internal combustion engine or compressor, which should actually be protected by the filter element. This results in increased wear or even damage to the machine assembly, which must be avoided.